Problem: if multibyte and binary string arguments passed to 
RPAD(), LPAD() or INSERT() functions, they might return 
wrong results or even lead to a server crash due to missed
character set convertion.

Fix: perform the convertion if necessary.


mysql-test/r/ctype_utf8.result:
  Fix for bug#57272: crash in rpad() when using utf8
    - test result.
mysql-test/t/ctype_utf8.test:
  Fix for bug#57272: crash in rpad() when using utf8
    - test case.
sql/item_strfunc.cc:
  Fix for bug#57272: crash in rpad() when using utf8
    - convert multibyte argument's character set to binary in case of
  FUNCTION(MULTIBYTE_ARG, .., BINARY_ARG,..) for RPAD(), LPAD() and 
  INSERT() functions.